A pick-up style utility vehicle typically includes a metal-made vehicle body, four wheels consisting of front wheels and rear wheels, an engine which is a driving source configured to generate a driving power, plural rows of seats on which passengers are seated, a cabin frame surrounding the seats from front and rear and from right and left, a cargo bed provided behind the seats, etc. In such a utility vehicle, it is desired that the cargo bed be required to have a large volume. However, the volume of the cargo bed is limited because the plural rows of seats occupy a space in a center section of the vehicle body. Accordingly, U.S. Pat. No. 6,905,159 discloses a utility vehicle in which two rows of seats are arranged and a rear seat is capable of being folded down forward so that a cargo bed is extendable in the resulting empty space.
In order to extend the cargo bed in this utility vehicle, it is necessary to remove a screen shield serving as a front wall member of the cargo bed before extending the cargo bed, to re-position the screen shield in a location corresponding to a front wall member of the extended cargo bed and to fasten the screen shield to the cargo bed by bolts and other members. The screen shield extends upward to spatially separate the cargo bed from a rear seat. An operation for removing and attaching the screen shield requires much labor and time. In view of the circumstances, there is a demand for a more simplified extension system for the cargo bed.